Copper and copper alloys, which are materials having low resistance, have been considered as wiring materials for display devices such as flat panel displays. However, copper has the problems that adhesion to a substance such as glass is not sufficient and copper diffuses into a silicon semiconductor film. In order to improve the adhesion between a wiring material and a glass substrate and prevent diffusion into a silicon semiconductor film, providing a molybdenum layer as a barrier film has been considered.
A laminate film containing copper or a copper alloy is etched using a resist as a mask and forms a wiring or electrode pattern. With regard to the performance required for etching, the forward taper shape in terms of the angle (taper angle) formed between an etching face of a copper wiring end part and a substrate as a lower layer is 30° to 60°, and the distance (side etching) between a resist end part and a barrier film provided beneath wiring is no greater than 1.2 μm, and preferably no greater than 1 μm.
As an etching solution for a copper and molybdenum laminate film, for example, an etching solution containing hydrogen peroxide, a hydrogen peroxide stabilizing agent, and at least one selected from a neutral salt, an inorganic acid, and an organic acid (Patent Document 1), an etching solution containing hydrogen peroxide, an inorganic acid containing no fluorine atoms, an amine compound, an azole, and a hydrogen peroxide stabilizer (Patent Document 2), etc. have been proposed.    [Patent Document 1] JP, A, 2002-302780    [Patent Document 2] International Patent Application WO2011/099624